Test enhancement

[peter279k]

Changed log

• Merge composer-travis-ci.json to composer.json.
• Using class-based PHPUnit namespace to be compatible with latest PHPUnit versions.
• Define multiple PHPUnit versions to support different PHP versions.

[mlocati]

We are missing coveralls in the new composer.json.
I think we need something like what I did in mlocati/ip-lib#21

[coveralls]

Coverage decreased (-3.6%) to 73.931% when pulling c0d40b4 on peter279k:test_enhancement into bff03c0 on mlocati:master.

[coveralls]

Coverage decreased (-3.6%) to 73.931% when pulling c0d40b4 on peter279k:test_enhancement into bff03c0 on mlocati:master.

[coveralls]

Coverage decreased (-3.6%) to 73.931% when pulling c0d40b4 on peter279k:test_enhancement into bff03c0 on mlocati:master.

[coveralls]

Coverage decreased (-3.6%) to 73.931% when pulling c0d40b4 on peter279k:test_enhancement into bff03c0 on mlocati:master.

[coveralls]

Coverage decreased (-3.6%) to 73.931% when pulling c0d40b4 on peter279k:test_enhancement into bff03c0 on mlocati:master.

[coveralls]

Coverage decreased (-3.6%) to 73.931% when pulling c0d40b4 on peter279k:test_enhancement into bff03c0 on mlocati:master.

[peter279k]

@mlocati, thank you for your comment.

I've added the "php-coveralls/php-coveralls": "^1.0" in composer.json and try to add the coveralls service back.

But it looks like the coveralls service has been broken because the code coverage percent is reduced.

It's strange because I don't do anything big changes for tests...